The present invention relates to a disc drive microactuator and suspension, and more particularly to a silicon-based thin film electromagnetic microactuator and suspension providing improved performance in response to an actuation force in a disc drive system.
The density of concentric data tracks on magnetic discs continues to increase (that is, the radial spacing between data tracks is decreasing), requiring more precise radial positioning of the head. Conventionally, head positioning is accomplished by operating an actuator arm with a large-scale actuation motor, such as a voice coil motor, to radially position a head on a flexure at the end of the actuator arm. The large-scale motor lacks sufficient resolution to effectively accommodate high track-density discs. Thus, a high resolution head positioning mechanism, or microactuator, is necessary to accommodate the more densely spaced tracks.
Various microactuator locations and designs have been considered to achieve high resolution head positioning. One promising design involves inserting a silicon-based thin film structure between the suspension and the slider in a disc drive assembly. The microactuator includes, for example, an electromagnetic transducer having magnetic core materials having a stator and a rotor, with conductive coils wrapped around the stator core in a solenoid-type or planar-type configuration. One of the technical challenges in implementing such a microactuator is to provide sufficiently large actuation force to overcome friction forces and spring bias forces to accelerate the head enough to accommodate the required bandwidth. Such a design must be realized in a relatively small wafer area, to keep costs reasonable and to allow easy integration into the disc drive design. It would also be useful for the microactuator to include a position sensor to discern the relative position of the movable portion of the microactuator.
A microactuator design achieving superior actuation force in a small wafer area is disclosed in U.S. application Ser. No. 09/010,100, now U.S. Pat. No. 6,122,149, issued Sep. 19, 2000, entitled xe2x80x9cMagnetic Microactuator and Inductive Sensor Having Shaped Pole Configuration,xe2x80x9d which is hereby incorporated by reference. There is a continuing need in the art for a microactuator suspension design to interface an improved microactuator motor such as is disclosed in U.S. application Ser. No. 09/010,100 with other disc drive components to achieve precise, high performance head positioning.
The present invention is a disc drive having a recording disc rotatable about an axis, a slider supporting a transducing head for transducing data with the disc, and a dual-stage actuation assembly supporting the slider to position the transducing head adjacent a selected radial track of the disc. The dual stage-actuation assembly includes a movable actuator arm, a suspension assembly supported by the actuator arm and including a flexure, a slider bond pad supporting the slider, and a microactuator. The microactuator includes a rotor attached to the slider bond pad and a stator attached to the flexure and operatively connected to the rotor to radially move the rotor with respect to the stator. At least one beam is attached between the slider bond pad and the stator.
Another aspect of the invention is a disc drive having a recording disc rotatable about an axis, a slider supporting a transducing head for transducing data with the disc, and a dual-stage actuation assembly supporting the slider to position the transducing head adjacent a selected radial track of the disc. The dual stage-actuation assembly includes a movable actuator arm, a suspension assembly supported by the actuator arm and including a flexure, a tongue supporting the slider, and a microactuator. The microactuator includes a rotor attached to the tongue and a stator attached to the flexure and operatively connected to the rotor to radially move the rotor with respect to the stator. First and second cross beams are each connected between the stator and the rotor and joined to form a pivot. The tongue extends from the pivot so that the slider is radially rotatable around the pivot.